1. Field of the Invention
This present invention relates to an electret capacitor microphone, particularly to a construction for permitting its surface mounting.
2. Background Art
Generally, an electret capacitor microphone is constructed such that a cylindrical metal case accommodates an electret capacitor section in which a diaphragm and a backplate are disposed to oppose each other, an impedance conversion element for converting a change in the electrostatic capacity of the electret capacitor section into an electric impedance, and a substrate on which this impedance conversion element is mounted.
This electret capacitor microphone is provided with a plurality of terminal members projecting from the substrate in the form of pins which are electrically conductive with the impedance conversion element. It is therefore structurally difficult to surface mount the electret capacitor microphone on an external substrate (e.g., a printed circuit board of a portable telephone or the like).
Accordingly, as described in JP-A-8-237797 for example, a measure is devised for surface mounting the electret capacitor microphone on an external substrate. In this measure, the electret capacitor microphone is fitted to a holder having contact pieces for surface mounting and is surface mounted on the external substrate via the holder.
However, with the above-described conventional electret capacitor microphone, it is necessary to interpose the holder at the time of surface mounting it on the external substrate. Accordingly, there occur problems such that an extra part becomes required and that the overall thickness becomes fairly large when the surface mounting is performed.